UPDATED: Moderna says Covid-19 boosters stand a fighting chance against new variants
A day before its second annual Vaccines Day, Moderna has posted an update on its crown jewel, including a 6-month look at the Covid-19 shot and new preclinical data that suggest its booster candidates stand a fighting chance against new variants.
Moderna’s variant-specific booster mRNA-1273.351, which was designed to target the B.1.351 mutation first identified in South Africa, “closed the neutralizing titer gap for variants of concern” in mice, the company said on Tuesday afternoon. When given at the 6-month mark, the booster elicited neutralizing titers against the variant that were comparable to those produced against the original virus.
mRNA-1273.211, a combination of mRNA-1273.351 and Moderna’s already authorized vaccine, also increased neutralizing titers against variants according to the preclinical results, which have been submitted to bioRxiv but haven’t been published.
“The new preclinical data on our variant-specific vaccine candidates give us confidence that we can proactively address emerging variants,” CEO Stéphane Bancel said in a statement. “Moderna will make as many updates to our COVID-19 vaccine as necessary until the pandemic is under control.”
Bancel told Endpoints News that he expects the virus to mutate very quickly in the next couple years, because a lot of people haven’t yet been vaccinated or infected. Then in 2023 or 2024, he predicts the speed at which the vaccine mutates could slow down.
“We think that in the next two years, there might be a need for several boosts, especially for people at high risk,” he said. “We think over time, maybe a boost per year might be enough, especially if combined with your flu boosts.”
As for the original vaccine, an updated review of 900-plus Covid-19 cases from the Phase III COVE study confirms the jab is more than 90% effective against all cases, and over 95% effective against severe cases. A study with 33 Phase I participants showed that antibodies persisted 6 months after the second dose, according to results published in the New England Journal of Medicine. Moderna believes efficacy kicks in two weeks after the second dose.
As part of its own updated review, Pfizer said its BioNTech-partnered jab demonstrated “strong protection” 6 months after the second dose, with an overall efficacy rate of 91.3%.
Moderna’s Phase II/III TeenCOVE study is fully enrolled with about 3,000 participants between the ages of 12 and 17 in the US, according to the company. That trial will assess a 100 µg dose of the vaccine. Meanwhile, the Phase II/III KidCOVE study is still recruiting children between 6 months and 11 years old. Moderna hopes to enroll 6,750 healthy participants in the US and Canada for the two-part dose escalation study. In Part 1, children between the ages of 2 and 12 will receive either 50 μg or 100 μg of the vaccine, and those who are younger will be given one of three dose levels — 25 μg, 50 μg or 100 μg. An interim analysis will determine which dose is used in Part 2.
The news comes as the US pauses the rollout of J&J’s vaccine to review data around six reported cases of a rare and severe type of blood clot. The CDC’s Advisory Committee on Immunization Practices is meeting tomorrow to further review these cases and assess their potential significance.
The EMA reported 3 cases of cerebral venous sinus thrombosis among the 4.5 million people vaccinated with J&J’s shot worldwide. By comparison, 169 cases of CVST and 53 cases of splanchnic vein thrombosis were reported among 34 million people who received the AstraZeneca vaccine in the EEA and UK. Thirty-five CVST cases were found worldwide among those who have received the Pfizer shot, and 5 for Moderna.
“A comprehensive assessment of the totality of the available safety data for mRNA-1273 after over 64.5 million doses administered globally does not suggest an association with CVST or thrombotic events, based on analyses performed using data through March 22, 2021,” Moderna said in a statement.
The CDC has issued a statement that its Vaccine Adverse Event Reporting System “has received no reports of CVST with thrombocytopenia among persons who received either of the two mRNA-based COVID-19 vaccines.”
As of April 12, Moderna had shipped out 132 million doses worldwide, including about 117 million to the US. Roughly 88 million doses were delivered to the US in Q1, in addition to about 14 million elsewhere. Plans are in place to ramp up the company’s ex-US supply chain.
Moderna says it’s on track to deliver 100 million doses to the US by the end of May, and another 100 million by the end of July.
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